Sheet tensioning and transfer mechanism for presses



March 4, 1969 c. o. SIEBKE 3,430,946

SHEET TENSIONING AND TRANSFER MECHANISM FOR PRESSES Filed Dec. 19, 1966Sheet of 5 m newm/a 641% 0. S/EBKE Sheet 2 o f CvO. SIEBKE SHEETTENSIONING AND TRANSFER MECHANISM FOR PRESSES March 4, 1969 Filed'Dec.19, 1966 5.5, E. J I RTFM 1 sh E wh 3 QM 3 6m 3 h M Q g Q Q 9 Qh Q 9 QWQQWW sh \N sg. Q as March 4, 1969 c. o. SIEBKE 3,430,946

SHEET TENSIONING AND TRANSFER MECHANISM FOR PRESSES Filed Dec. 19, 1966Sheet 3 of 3 w in? ATTORNEY United States l atent C 3,430,946 SHEETTENSIONING AND TRANSFER MEQHANISM FOR PRESSES Carl 0. Siebke,Pittsburgh, la, assignor to Miller Printing Machinery (30., Pittsburgh,Pa, a corporation of Pennsylvania Filed Dec. 19, 1966, Ser. No. 602,857

US. Cl. 271-51 20 Claims Int. Cl. 1365b 5/12, 5/14 ABSTRACT OF THEDISCLOSURE Apparatus in a rotary press sheet transfer cylinder forpulling a sheet taut on the outer surface or periphery of the cylinder.Suction devices positioned on the periphery of the cylinder are securedto arm members that are in turn secured to an actuating shaft supportedwithin the cylinder. The trailing edge of the sheet to he transferred isengaged by the suction devices and the shaft with the arms securedthereto is rotated to pull the sheet taut over the peripheral surface ofthe cylinder.

BACKGRCUND OF THE INVENTION Field of the invention This inventionrelates to a sheet handling device for holding and tensioning a sheet ona cylinder and more particularly to a sheet handling device fortensioning a paper sheet on the outer surface of a printing presstransfer cylinder.

Description of the prior art In the past, as described in Patent No.2,757,610 to Gegenheimer et al. entitled Sheet Handling Mechanism andMethod for Multi-Color Perfector Press, granted Aug. 7, 1956, thetransfer cylinder of a rotary press was provided with suction heads tohold the trailing edge of the paper sheet on the cylinder duringrotation and transfer thereof. The suction heads were fixed relative tothe cylinder and the paper sheet had to be delivered to the cylinder ina flat wrinkle free condition in order to transfer the sheet in a smoothand unwrinkled condition. There was no provision in Patent N0. 2,757,610for tensioning the sheet of paper after it was positioned on thecylinder.

Patent No. 3,096,088. to Young entitled, Sheet Holding and TransferMechanism for Presses, granted on July 2, 1963, discloses apparatus forpulling and tensioning the sheet on the transfer cylinder by moving thesuction heads along the periphery of the cylinder after the suctionheads have engaged the trailing edge of the paper sheet. The suctionheads are arranged to move on the cylinder peripheral surface in adirection away from the leading edge of the sheet and thus pull thesheet into a smooth and taut condition on the cylinder.

In the above discussed prior art patents to Young and Gegenheimer etal., the sheet transfer cylinder is provided with gripping means forreceiving and gripping the leading edge of the sheet to be transferred.The suction heads on the peripheral or external surface of the cylinderare spaced from the gripping means a preselected distance so that thesuction heads are beneath the trailing edge of the sheet. By applying asuction the trailing edge of the sheet is engaged by the suction headsand held on the cylinder. The suction heads of Young are urged bysprings toward the gripping means. After the trailing edge of the sheetis in overlying relation with and secured to the suction heads bysuction, the suction heads are moved away from the gripping meansagainst the opposing force of the internal springs by suction. It isthis movement of the suction heads that tensions the sheet and draws ittaut over the surface of the transfer cylinder.

It is essential in pulling and tensioning the sheet on the externalsurface of the cylinder that all of the suction heads move away from thegripping means simultaneously and traverse the same distance in order toevenly tension the entire sheet on the transfer cylinder. Smallvariations in the resiliency of the internal springs within the suctionheads may cause one or more of the suction heads to move sooner than theother suction heads or may cause the suction heads to move differentdistances relative to the gripping means. This results in the sheetbeing pulled or tensioned unevenly over the periphery of the cylinder.

Further, in Young the suction for engaging the sheet to the suction headand compressing the internal springs to move the suction heads isobtained from the same source so that the suction must be sufficient toengage the sheets to the suction heads and also sufficient to compressthe internal springs and move the suction heads away from the grippingmeans. Using the same suction for both operations may also cause uneventensioning of the sheet on the transfer cylinder. In addition, forcertain types of paper, such as tissue paper, the suction required tocompress the internal springs within the suction heads may be excessive.A fixed minimum suction is required to compress the internal springswithin the suction heads. This minimum suction may exceed the strengthof the tissue paper to the extent that the tissue paper is damaged whensubjected to this excessive suction through the suction heads. If thesuction is reduced to prevent damage to the tissue paper, insufiicientsuction is present to compress the internal springs and properly tensionthe sheet of tissue paper on the transfer cylinder.

SUMMARY OF THE INVENTION The present invention eliminates the abovediscussed problems by providing a mechanical means for moving thesuction heads away from the gripping means for tensioning the sheet onthe transfer cylinder. The suction applied to the suction heads issolely for engaging the sheet to the suction head. Where tissue orfragile paper is being processed the suction can be reduced to a minimumthat does not damage the paper and the mechanical means, independent ofthe suction pressure, is operable to move the suction heads away fromthe gripping means. The suction heads are all interconnected to themechanical means and move simultaneously the same distance along thecylinder periphery to thereby apply an even tension to the sheet.

Briefly, the present invention provides a sheet transfer cylinder havinggripping means for receiving and gripping the leading edge of the sheetto be transferred. A sheet engaging device having suction heads on theperiphery of the cylinder is operable to engage the trailing edge of thesheet by suction. The sheet engaging device is movably mounted withinthe body of the cylinder so that the suction heads are movable along theperiphery of the cylinder toward and away from the gripping means. Amechanical means including an actuator positioned externally of thecylinder is arranged to move the sheet engaging device so that thesuction heads move toward the gripping means to engage the trailing edgeof the sheet and thereafter move the sheet engaging device so that thesuction heads move away from the gripping means to draw the sheet tautover the outer surface or periphery of the cylinder.

Accordingly, it is the principal object of the present invention toprovide a mechanically actuated device for moving a sheet engagingmember toward and away from the gripping means to thereby evenly tensionthe sheet on the periphery of the cylinder.

Another object of this invention is to connect a plurality of sheetengaging members to each other so that all of the sheet engaging memberswill simultaneously move away from the gripping means along theperiphery of the cylinder.

Another object of this invention is to provide a suction type sheetengaging member in which the sole function of the suction is to engagethe sheet to the sheet engaging member.

These and other objects and advantages of this invention will be morecompletely disclosed and described in the following specification, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIGURE 1 is a schematic end view of a second transfer cylinderillustrating a paper sheet on the second transfer cylinder after thesecond transfer cylinder has received the sheet from a first transfercylinder. The suction heads are in a first position away from thegrippers and abutting a stop member.

FIGURE 1A is a view similar to FIGURE 1 illustrating the second transfercylinder rotated on its axis to a position where the suction heads havemoved to a second position toward the grippers and spaced from the stopmember.

FIGURE 2 is a view similar to FIGURE 1A illustrating the second transfercylinder further rotated on its axis to a position where the suctionheads engage the trailing edge of the sheet. The paper sheet isillustrated with several wrinkles therein.

FIGURE 3 is a view similar to FIGURE 2 illustrating the second transfercylinder still further rotated on its axis with the suction headsengaging the trailing edge of the sheet with the suction heads movedback to the first position away from the grippers. The movement of thesuction heads away from the grippers has removed the wrinklesillustrated in FIGURE 2.

FIGURE 4 is a developed view of the transfer cylinder taken along theline 44 in FIGURE 5 illustrating the sheet engaging device and themechanical actuation therefor.

FIGURE 5 is a fragmentary end view in elevation of the transfer cylinderillustrating the mechanical actuating means for the sheet engagingdevice taken generally along the line 5-5 in FIGURE 4.

FIGURE 6 is a view in side elevation of one of the sheet engaging vacuumarms.

FIGURE 7 is a plan view of the suction head secured to the top portionof the vacuum arm.

FIGURE 8 is a view in front elevation of a sheet engaging vacuum armmounted on a support shaft having a passageway therethrough.

FIGURE 9 is a side view in elevation taken along the line 99 in FIGURE 4illustrating the cam disc for rotating the vacuum arms and actuating thesuction valve. The cam disc is mounted on the frame of the rotary press.

FIGURE 10 is a developed view of the cam surface for actuating thesuction valve illustrated in FIGURE 9.

FIGURE 11 is a side view in elevation illustrating one of the shaftsupporting discs taken generally along the line 1111 in FIGURE 4.

FIGURE 12 is a view similar to FIGURE 5 illustrating another embodimentof an actuating means for the sheet engaging vacuum arms.

FIGURE 13 is a side view in elevation of an actuating disc havingcontact surfaces for the actuating means illustrated in FIGURE 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings andparticularly to FIGURES 1-3 there is shown schematically an end view ofa second transfer cylinder generally described by the numeral 10. Thetransfer cylinder 10 is supported and mounted for rotation in the frameof a rotary press on shaft 12. Two sets of gripper fingers are showngenerally at 14 and 16 mounted on the periphery of the cylinder 10 togrip the leading edge of a sheet to be transferred by the transfercylinder 10. Two sets of suction heads shown generally at 18 and 20 aremovable along the periphery of the cylinder for engaging the trailingedge of the sheets to be transferred. Suction heads 18 and 20 aremounted on sheet engaging vacuum arms generally designated by thenumerals 22 and 24 which are in turn nonrotatably secured to vacuum armshaft generally designated 26 and 28 respectively. Vacuum arm shafts 26and 28 are supported by the second transfer cylinder 10 and have an axisparallel to and spaced from the cylinder axis of rotation.

The general operation of the transfer cylinder in engaging andtensioning a sheet is as follows. As the transfer cylinder 10 rotates onits axis in the direction of the arrow in FIGURE 1, the leading edge 30of a sheet 32 that is to be transferred by the cylinder 10 is taken froma first transfer cylinder 34 by the gripper fingers 14 in the mannerdescribed in Patent No. 2,757,610, included herein by reference, andtransferred to the transfer cylinder It). In the position illustrated inFIGURE 1, the vacuum arms 24 abut stop members 132 and the suction heads20 are in a first position away from the gripper fingers 14.

In FIGURE 1A, the second transfer cylinder 10 has rotated about its axisto a position where the vacuum arms 24 have moved toward the grippers14. The trailing edge 36 of sheet 32 is not as yet in overlying relationwith the suction heads 20. The suction heads 20 have moved toward thegrippers 14 by rotation of the shaft 28 in the direction of the arrow inFIGURE 1A.

In FIGURE 2, the second transfer cylinder 10 has further rotated aboutits axis from the position illustrated in FIGURE 1A and the trailingedge 36 of sheet 32 is in overlying relation with the suction heads 20.Suction is applied to the suction heads at approximately the positionillustrated in FIGURE 2 to engage the trailing edge 36 of the sheet 32to the respective suction heads 20. The sheet 32 may have a nonplanarconfiguration and contain wrinkles generally designated by the numerals38 and 40.

After the trailing edge of the sheet is engaged by the suction heads 20,on further rotation of the second transfer cylinder 10, as illustratedin FIGURE 3, the shaft 28 is rotated in the direction of the arrow inFIGURE 3 opposite to the direction illustrated in FIGURE 2. Thisrotation of shaft 28 moves the suction heads 20 along the periphery ofcylinder 10 away from the grippers 14 to thereby pull the sheet 32 bythe trailing edge 36 taut over the periphery of the cylinder 10 andremoves the wrinkles 38 and 40 previously present in the sheet 32. Therotation of shaft 28 first in one direction and then in the oppositedirection occurs while the cylinder 10 is rotating in one directionabout the axis of shaft 12.

EMBODIMENT IFIGURES 41l FIGURES 4-11 illustrate one embodiment of themechanical actuating mechanism for moving suction heads 18 and 20.FIGURE 4 is a developed section and illustrates one set of vacuum armsand one set of gripper fingers which for convenience will be generallyreferred to, respectively, by the numerals 16 and 18. In the No. 2transfer cylinder of a multi-color and perfector press, as described inPatent No. 2,757,610, there are two sets of gripper fingers and two setsof suction heads. It should be understood, however, the hereinafterdescribed invention is applicable to sheet handling devices having oneor more sets of gripper fingers and one or more sets of suction heads.

In FIGURE 4, the shaft 12 of transfer cylinder is of tubularconstruction and is mounted for rotation in journals 42 and 44 in framemembers 46 and 48 respectively. Secured to the tubular portion of mainshaft 12 are a plurality of spaced sheet supporting discs generallydesignated by the numeral 50 that have a hub portion 52 and radiallyextending disc like spokes or web portions 54. The web portions 54 haveradial flanged sheet supporting end portions 56 that are arranged tosupport the paper sheet. The external surface of the cylinder sheetsupporting portions 56 form the outer periphery of the transfer cylinder10".

The sheet supporting disc web portions have elongated semicircularopenings 58 therein to permit adjustment of the vacuum arm shaft 26toward and away from the gripper fingers 16 as will be later described.

Also supported on the tubular portion of main shaft 12 are a pluralityof shaft supporting discs generally designated by the numeral 60(FIGURES 4 and 11) and each has a hub portion 62 secured to the mainshaft 12. Disc like web portions 64 extend radially from the hub portion62 and have flanged radial sheet supporting peripheral segments 66 thatare also arranged to support the sheet on the transfer cylinder outersurface. The sheet supporting segments 66 are in the same cylindricalplane as the sheet supporting surfaces 56 of sheet supporting discs 50.

The shaft supporting discs 60- have aligned passageways 68 therethroughin which bearings 70 are positioned. The vacuum arm shaft 26 extendsthrough the axially aligned passageways 68 and is rotatably supported bythe bearings 70. The web portions 64 of certain of the shaft supportingdiscs 60 have aligned passageways 72 for a valve actuator shaft andpassageways 74 and 76 for air and suction conduits later described. Theshaft supporting discs 60 are adjustable on the shaft 12 to move thesuction heads 18 and toward or away fiom the grippers 14 and 16 so thatthe suction heads 18 and 20 may be positioned beneath the trailing edgeof paper sheets having different lengths.

The vacuum arm shaft 216 has a plurality of vacuum arms generallydesignated by the numeral 22 secured thereto and rotatable therewith.One of the vacuum arms 22 is illustrated in detail in FIGURES 6, 7 and 8and includes a body portion 78, a hub portion 80 and a suction headreceiving end portion 82. The suction head receiving portion 82 has anupper suction head receiving surface 84 and a bottom surface 86. Apassageway 88 extends from the bottom surface 86 through the suctionhead receiving end portion 82 to the upper surface 84. The suction head18 has a perforated or foraminous top surface 92 and is secured to thesuction head receiving portion top surface 84 by screws 94. The suctionhead 18 has a chamber 96 connected to the passageway 88 in the vacuumarm end portion 82 so that the chamber 96 may be. evacuated by applyinga suction or vacuum to the passageway 88 or air under pressure may besupplied to chamber 96 through passageway 88 as will be later described.The suction heads 18, for convenience of description, are called suctionheads although it should be understood the heads 18 also serve as blowerheads.

The suction head end portion 82 also has a bore 98 therethrough normalto and intersecting passageway 88. A manually rotatable valve 100 ispositioned in bore 98 and is operable to open and close passageway 88.The valve 100 is locked in position by a spring 102 secured to thesuction head receiving end portion 82 by a screw 104. A flexible conduit106 is connected at one end to the passageway 88 in the suction headreceiving end portion 82 and at the other end to an opening 108 in thevacuum arm shaft 26. The vacuum arm shaft 26 has an axial bore 110 thatis connected to the conduits 106 at the openings 168. Air or suction isprovided for the suction heads 18 through the axial bore 110 in vacuumarm shaft 26 as later described.

As is apparent from FIGURES 4 and 11, the axis of the vacuum arm shaft26 is spaced radially from the axis of the transfer cylinder main shaft12 and is parallel thereto. The vacuum arm shaft 26 is also spacedinwardly from the periphery of the transfer cylinder 10 and the vacuumarms 22 extend radially toward the periphery of the cylinder 10 with thesuction heads 18 positioned in the same plane as the sheet supportingsurfaces of the discs 50 and 60.

Secured to the end of cylinder main shaft 12 adjacent the frame 48 is asupport member 112 that it rotatable with the cylinder 10. The supportmember 112 has an annular body portion 113 with a radially extendingsupport portion 114. The vacuum arm shaft 26 has an end portion 116extending through a passageway 118 (FIG- URE 4) in the radiallyextending support portion 114 .and is rotatably supported therein. Anactuating lever 120 is nonrotatably secured to the vacuum arm shaft endportion 116 and is operable to rotate the vacuum arm shaft 26 in thesupport passageways 118 and 68. A cam roller 122 is rotatably connectedto the end of lever .120. The lever 120 has a pin 124 connected theretoand loosely positioned in a bracket 126 secured to the annular member112. A spring 128 is positioned around pin 124 and urges the lever awayfrom the annular member 112. The spring 128 exerts a force on the end oflever 120 to rotate the vacuum arm shaft 26 in a clockwise direction asviewed in FIGURES 5 and 11. Each of the shaft supporting discs 60 has aradially extending stop portion 130 with an adjustable stop member 132positioned therein. The spring 128 through lever 120 and vacuum armshaft 26 urges the vacuum arms 22 against the end of stop member 132 tothereby maintain the suction heads 18 in a position away from thegrippers 16. By rotating the vacuum arm shaft 26 through lever 120 in acounterclockwise direction, as viewed in FIGURES 5 and 11 the suctionheads 18 are moved in a direction toward the grippers 16.

Referring to FIGURES 4 and 9, a cam disc .134 is secured to the innersurface of frame 48 and has a radially inwardly extending cam segment136 with a cam surface 138. The cam roller 122 (FIGURES 4 and 5) on theend of lever 120 is arranged to contact the cam surface 138 duringrotation of the cylinder 10 to move lever 120 in a direction to compressspring 128. The cam surface 138 thus through cam roller 122, lever 120and vacuum arm shaft 26 moves the suction heads 18 on vacuum arms 22toward the grippers 16 a preselected distance. This distance iscontrolled by the shape and dimensions of the cam 136.

The mechanism for applying suction to the suction heads 18 isillustrated in FIGURE 4. The intermediate shaft support disc 60 has avalve housing 140 with an air port 142 and a vacuum or suction port 144.An air pressure conduit 146 is connected to the air port 142 and issupported in the shaft supporting discs 60 and extends through apassageway 148 in the radially extending portion 114 of support member112. A suction conduit 150 is connected to the suction port 144 andextends through a similar passageway 152 in the support member 112. Anannular rotary valve generally designated by the numeral 154 is mountedon the shaft 12 and has a rotatable portion 156 secured to and rotatablewith the cylinder 10 and a fixed portion 158 connected to the framemember 48 by a pin 160. The conduits 146 and 150 have their end portionsconnected to the rotatable portion 156. The rotatable portion 156 andfixed portion 158 have annular recessed portions 162 and 164 thatcommunicate with the respective air and suction conduits 146 and 150through suitable passageways in the valve rotatable portion 156. Asource of suction such as a conventional vacuum pump (not shown) isconnected through conduit 166 to the valve fixed portion 158 and isarranged to provide a suction through annular passageway 162 to thesuction conduit 150. There is a similar source of air under pressure(not shown) connected to a conduit 168 (FIGURE that supplies air underpressure through suitable passageways in the valve fixed portion 158 toannular passageway 164 and air conduit 146. With this arrangement, airunder pressure is provided in conduit 146 and a suction is provided inconduit 150. Suitable annular seal means are positioned between thefixed and rotatable portions of valve 154 to seal the respective annularpassageways 162 and 164.

The valve 140 has a chamber 168 connected to air port 142 and suctionport 144. There is an outlet port 170 in valve housing 140 thatcommunicates with the axial bore or passageway 110 in the vacuum armshaft 26. A rod-like valve member 172 is positioned in chamber 168 andis arranged to alternatively connect outlet port 170 with air port 142or suction port 144. The rod-like valve member 172 is connected to a rod174 that is supported in the shaft supporting discs 60 and has an endportion connected to an actuator 176 supported in a passageway 178 inthe radially extending portion 114 of support member 112. The valve 172has .a spring member 180 that normally biases the valve member to aposition where the air port 142 is connected to outlet port 170. Bymoving the rod axially against the spring 180 (as is illustrated inFIGURE 4), the airport 142 is closed and the suction port 144 isconnected to the outlet port 170. The rod 174 is arranged to moveaxially to connect the respective air and vacuum ports 142 and 144 tothe outlet port 17 0. The actuator 176 supported in support member 112has a cam roller 182 on its end portion.

The actuator for valve 140 is a semicircular cam segment 184 on cam disc134 illustrated in FIGURES 9 and 10. The cam segment 184 has a camsurface 186 that extends inwardly toward the transfer cylinder 10. FIG-URE is a developed view of the cam segment 184 and illustrates theinwardly extending raised cam surface 186. Upon rotation of the cylinder10, the roller 182 rotatably secured to valve actuator 176 contacts thecam surface 186 and moves the valve rod 174 inwardly to the positionillustrated in FIGURE 4 to connect the suction port 144 in valve housing140 to the outlet port 170 and thus provide a suction for suction heads18. It should be noted that the cam surfaces 186 and 138 are arranged inthe same quadrant so that the suction head is subjected to a suctionpressure when the lever 120 moves the vacuum arms 22 and suction heads18 away from the grippers 16.

The vacuum arms 22 and their associated structure may be moved towardand away from the grippers to accommodate different sized sheetsprocessed in the rotary press. A clamp screw (not shown) may be loosenedto adjust the annular support member 112 (FIGURE 5) and the annularsupport member 112 with the associated structure positioned thereon maybe rotated relative to the cylinder main shaft 12 with the vacuum arms22 and their associated structure about the axis of main shaft 12 withinthe limits of the elongated semicircular openings 58 in the sheetsupporting discs 50. A pointer 188 extends radially from the annularsupport member body portion 113 and cooperates with an index plate 190mounted on the sheet supporting disc 50 adjacent the end of cylinder 10to indicate the arcuate distance between the grippers 16 and the suctionheads 18 on the periphery of the cylinder 10. This arcuate distance isequivalent to the length of the sheet that may be processed in therotary press with the trailing edge of the sheet in overlying relationwith the suction heads 18 when the front edge of the sheet is engaged bythe grippers 16.

The transfer cylinder 10 is driven by drive gears 192, as illustrated inFIGURE 4 and the grippers 16 that are associated with the cylinder 10are generally illustrated in FIGURE 4. There is also illustratedgenerally actuating mechanisms 194 for the grippers 16 and a cam 196secured to the inner surface of frame 46 for opening and closing thegrippers 16. The mechanism for rotating the transfer cylinder 10, thegrippers and the arrangement for actuating the grippers is similar tothat described in the Gegenheimer et al. Patent No. 2,757,610. Theapparatus and method of operation illustrated and described in theGegenheimer et al. Patent No. 2,757,610 is incorporated herein byreference.

EMBODIMENT IIFIGURES 12 AND 13 In FIGURES l2 and 13 there is illustratedan electromechanical device for moving the suction heads 18 toward andaway from the grippers 16. FIGURE 12 is similar to FIGURE 5 and similarnumerals will designate similar parts. A solenoid generally designatedby the numeral 198 is supported by an extension of bracket 126. Thesolenoid 198 has a solenoid coil 199 and a cylindrical core or armature200. The armature 200 is connected to lever by means of a pivot link202. The solenoid 198 has a flange member 204 extending therefrom thatsupports a pair of brushes 206 and 208. The flange memher 204 ispreferably resilient to urge the brushes 206 and 208 against contactsurfaces on a disc 210 generally illustrated in FIGURE 13. Suitableconductors (not shown) connect the brushes 206 and 208 with the solenoidcoil 199 so that current from brushes 206 and 208 will energize coil 199creating a magnetic flux and pulling armature 200 inwardly in coil 199.

The disc 210 is similar to the cam disc 134 to the extent that cammember 184 is secured thereto and has a cam surface 186 similar to thatillustrated in FIGURE 9 to actuate the valve member 172, as previouslydiscussed. The disc 210 has appropriate circular contact surfaces 212and 214 on which the brushes 206 and 208 ride upon rotation of cylinder10. The contact surfaces 212 and 214 have appropriate electricallyconductive portions 216 and 218 for the segment illustrated by the lineA in FIGURE 13. The remainder of the contact surfaces are nonconductivesurfaces.

As the cylinder 10 rotates, the brushes 206 and 208 remain in contactwith the circular contact surfaces 212 and 214 and as the brushestraverse the electrically conductive portions 216 and 218, the brushes206 and 208 complete an electrical circuit through surfaces 216 and 218to energize the solenoid coil 199. When the coil 199 is energized, thecore or armature 200 moves inwardly and rotates the lever 120 and vacuumarm shaft 26 in a counterclockwise direction, as viewed in FIGURE 12, tomove the suction heads 18 toward the grippers 16 and further compressesspring 128 in a manner similar to that previously described. When thecylinder rotates to a position where the brushes 206 and 208 contact thenonconductive portions of contact surfaces 212 and 214, the spring 128expands and rotates the lever 120, vacuum arm shaft 26 and vacuum arms22 until the vacuum arms 22 abut the stop member 132 (FIGURE 11) andthus move the suction heads 18 away from the grippers 16.

OPERATION In operation, the transfer cylinder 10 is rotated at apreselected speed by the drive gears 192. The leading edge of the sheetthat is transferred from the #1 transfer cylinder 34 (FIGURE 1) isengaged by the grippers 16 in the manner described in Patent No.2,757,610. The grippers secure the leading edge of the sheet to thetransfer cylinder 10 and the body of the sheet assumes the curvature ofthe transfer cylinder 10. The vacuum arms 22 and associated apparatus isadjusted relative to the grippers 16 by adjusting annular support member112 so that the trailing edge of the sheet will be in overlying relationwith the suction heads 18. Before the trailing edge of the sheet is inoverlying relation with the suction heads 18, the cam roller 122associated with lever 120 contacts the cam surface 138 on cam member 136and rotates the lever 120, vacuum arm shaft 26 and vacuum arm 22 andmoves the vacuum arms and suction heads toward the grippers 16 to aposition similar to that illustrated in FIGURE 1A. The suction heads aremoved toward the grippers 16 before the suction heads reach the commoncenter line between the second and first transfer cylinders 10 and 34.The cam roller 1'82 associated with the valve actuator 176 then contactsthe raised cam surface 186 on the semicircular cam member 184 to movethe valve actuator 176 and valve stem 172 to the position illustrated inFIGURE 4 to thus connect the outlet port 170 with suction port 144 toprovide a suction in suction heads 18. The suction heads are inapproximately the position illustrated in FIGURE 2 when the suction isapplied thereto. The trailing edge of the sheet is thus engaged by thesuction heads 18 by suction.

While the sheet trailing edge remains engaged to the suction heads bythe suction, the cam roller 122 moves off the cam surface 138 and spring128 expands and rotates the lever 120 and vacuum arm shaft 22 in aclockwise direction to thereby rotate the vacuum arms 22 and move thesuction heads 18 away from the grippers 16. The cam surface 138 is soarranged that the vacuum arms 22 move away from the grippers 16 a shorttime after the suction heads 20- have passed the common center linebetween the second and first transfer cylinders 10 and 34 as isillustrated in FIGURE 3. This movement of the suction heads 18 away fromthe grippers 1-6 by the expansion spring 128 while the trailing edge ofthe sheet is engaged by the suction heads 18, pulls the paper sheetengaged by grippers 16 taut on the surface of cylinder 10. The suctionheads 18 remains in this latter position away from the grippers 16 underthe force of spring 128 until again urged toward the grippers 16 by thecam actuated lever. Further rotation of cylinder 10 moves cam roller 182associated with valve actuator 176 off of the raised cam surface 186 tomove the valve 172 to open the air port 140 to outlet port 170. Thepositive air pressure exerted through the suction heads 18 disengagesthe trailing edge of the sheet from the suction heads. This latteroperation is accomplished as the sheet is being transferred from the #2transfer cylinder and is engaged by grippers on a subsequent transfercylinder. As the transfer cylinder 10 picks up another sheet of paper,the above sequence is repeated thus tensioning each sheet as it istransferred by transfer cylinder 10.

With this arrangement, the amount of suction in suc tion heads 18 isdetermined by the engaging force required between the trailing edge ofthe paper sheet and the suction head. The mechanical actuating meansi.e. cam 136, lever 120, vacuum arm shaft 26, vacuum arms 22 and spring128, move the suction heads toward and away from the grippers 16 and isindependent of the suction pressure in the suction heads 18. Because allof the vacuum arms 22 are fixedly secured to the vacuum arm shaft 26,all of the suction heads move simultaneously toward and away from thegrippers 16 and move the same incremental distance along the peripheryof the transfer cylinder 10. The sequence of subjecting the suctionheads 18 to a suction and moving the suction heads toward and away fromthe grippers is controlled by the relative positions of the cam members136 and 184. It should be understood that the cam arrangement could besuch that the suction heads 18 would be moved away from the grippers 16upon actuation by a cam surface and moved toward the grippers by anothermechanical device.

The electromechanical actuating mechanism in FIG- URES 12 and 13operates in a similar manner to the actuating mechanism illustrated inFIGURES 4-11. The lever arm is moved in a counterclockwise direction bymeans of the solenoid 198. The brushes 206 and 208 and the conductivecontact surfaces 216 and 218 control the segment where the solenoid coil199 is energized and the armature 200 is pulled into the coil 199 tomove lever 120 and rotate the vacuum arm shaft 26. In the embodimentillustrated in FIGURES 12 and 13, the air suction valve is actuated by araised cam mechanism 186. It should be understood, however, that theair-vacuum valve could also be actuated by a similar electrical deviceas that illustrated in FIGURE 12 for rotating lever 120.

According to the provisions of the patent statues, I have explained theprinciple, preferred construction, and mode of operation of my inventionand have illustrated and described what I now consider to represent itsbest embodiments. However, I desire to have it understood that, Withinthe scope of the appended claims, the invention may be practicedothervvise than as specifically illustrated and described.

I claim:

1. A sheet handling device comprising:

a sheet transfer cylinder having gripper means for receiving andgripping the leading edge of a sheet to be transferred,

sheet engaging means extending toward the periphery of said cylinderadjacent the trailing edge of said sheet,

said sheet engaging means having a sheet engaging portion movable alongthe periphery of said cylinder operable to engage said trailing edge ofsaid sheet,

first mechanical means operable to move said sheet engaging portion ofsaid sheet engaging means away from said gripper means,

adjustable stop means on said cylinder to limit move ment of said sheetengaging means in a direction away from said gripper means,

second mechanical means operable to move said sheet engaging portiontoward said gripper means,

said first mechanical means and said second mechanical means beingoperable to move said sheet engaging portion toward said gripper meansfor engaging the trailing edge of said sheet and thereafter moving saidsheet engaging portion away from said gripper means while said grippermeans engages said leading edge of said sheet to thereby draw said sheettaut over the periphery of said cylinder.

2. A sheet handling device as set forth in claim 1 in which said sheetengaging portion includes:

a suction head for engaging the sheet to be transferred,

valve means within said transfer cylinder,

conduit means connecting said valve means to said suction head,

cam actuated means controlling said valve means.

3. A sheet handling device as set forth in claim 1 in which:

said second mechanical means includes a lever means operable to movesaid sheet engaging portion of said sheet engaging means toward saidgripper means.

4. A sheet handling device as set forth in claim 3 in which:

said lever means includes roller means rotatably secured thereto,

a cam member positioned adjacent to said cylinder,

said cam member having a cam surface fixed relative to said cylinder,

said roller means being operable to engage said cam surface and rotatesaid lever means to thereby move said sheet engaging portion toward saidgripper means.

1 1 5. A sheet handling device as set forth in claim 3 in which:

said lever means includes electrically actuated means secured thereto,said electrically actuated means being operable to rotate said levermeans to thereby move said sheet engaging portion toward said grippermeans. 6. A sheet handling device as set forth in claim 1 in which:

said sheet engaging means includes a vacuum arm eX- tending to theperiphery of said cylinder, said vacuum arm having a sheet engaging endportion movable along the periphery of said cylinder, said sheetengaging end portion being operable to engage said trailing edge of saidsheet, said second mechanical means includes electrically actuated meansto rotate said vacuum arm toward said gripper means. 7. A sheet handlingdevice as set forth in claim 6 in which:

said electrically actuated means includes a solenoid coil secured tosaid cylinder with a movable core positioned therein, said coreconnected to said vacuum arm so that upon energization of said solenoidcoil said core moves into said solenoid and rotates said vacuum arm tothereby move said vacuum arm sheet engaging end portion toward saidgripper means. 8. A sheet handling device as set forth in claim 1 inwhich:

said first mechanical means includes resilient means urging said sheetengaging portion of said sheet engaging means away from said grippermeans. 9. A sheet handling device as set forth in claim 8 in which:

said resilient means urges said sheet engaging portion of said sheetengaging means away from said gripper means, said second mechanicalmeans being operable to move said sheet engaging portion of said sheetengaging means against said resilient means toward said gripper means.10. A sheet handling device as set forth in claim 8 in which:

said sheet engaging means includes support means within said cylinder,said support means being secured to said second mechanical means, saidsecond mechanical means being operable to rotate said support means tothereby move said sheet engaging portion of said sheet engaging meansagainst said resilient means toward said gripper means. 11. A sheethandling device as set forth in claim 1 in which:

said sheet engaging means includes a vacuum arm extending to theperiphery of said cylinder, said vacuum arm having a sheet engaging endportion movable along the periphery of said cylinder, said sheetengaging end portion being operable to engage said trailing edge of saidsheet, said second mechanical means includes cam actuated means torotate said vacuum arm toward said gripper means. 12. A sheet handlingdevice as set forth in claim 11 in which:

said cylinder includes adjustable stop means for said vacuum arm, saidadjustable stop means being operable to limit the movement of saidvacuum arm in a direction away from said gripper means. 13. A sheethandling device as set forth in claim 11 in which:

said first mechanical means being operable to urge said vacuum arm endportion away from said gripper means, said cam actuated means beingoperable to move said end portion toward said gripper means,

said first mechanical means and said cam actuated means being operableto move said vacuum arm end portion toward said gripper means to a sheetengaging position with said trailing edge of said sheet and thereaftermove said vacuum arm end portion away from said gripper means after saidtrailing edge of said sheet has been engaged by said vacuum arm endportion to thereby draw said sheet taut over the periphery of saidcylinder.

14. A sheet handling device as set forth in claim 11 in which:

said cam actuated means includes support means for said vacuum arm, saidvacuum arm being nonrotatably secured to said support means,

said cam actuated means being operable to rotate said support means andsaid vacuum arm nonrotatably secured thereto to thereby move said vacuumarm sheet engaging end portion toward said gripper means.

15. A sheet handling device as set forth in claim 14 in which:

said first mechanical means includes resilient means connected to saidcam actuated means, said resilient means being operable to rotate saidsupport means and move said vacuum arm sheet engaging end portion awayfrom said gripper means to thereby draw said sheet taut over theperiphery of said cylinder.

16. A sheet handling device as set forth in claim 14 in which:

said support means includes a shaft rotatably supported within saidtransfer cylinder in parallel relation to the axis of rotation of saidcylinder.

17. A sheet handling device as set forth in claim 11 in which:

said cam actuated means includes support means for said vacuum arm, saidvacuum arm being nonrotatably secured to said support means, said camactuated means includes a lever nonrotatably secured to said supportmeans, said lever being operable to rotate said support means to therebymove said vacuum arm sheet engaging end portion toward and away fromsaid gripper means, said first mechanical means includes a springconnected to said lever, said spring being operable to rotate saidsupport means and move said vacuum arm sheet engaging end portion awayfrom said gripper means,

said cam actuated means including a roller member rotatably secured tosaid lever and a cam member positioned adjacent to said cylinder, saidcam member having a surface fixed relative to said cylinder,

said roller means being operable to engage said cam surface uponrotation of said cylinder and rotate said lever and said support meansto thereby move said vacuum arm sheet engaging end portion toward saidgripper means.

18. A sheet handling device comprising a sheet transfer cylinder havinggripper means for receiving and gripping the leading edge of a sheet tobe transferred and sheet suction engaging means movable along theperiphery of said cylinder to engage the trailing edge of the sheet:

said sheet suction engaging means including a sheet engaging portionsubstantially tangent with said cylinder periphery and a supportingportion rotatably mounted within the body of said cylinder,

suction means being connected with said sheet engaging portion toprovide a controlled vacuum for holding the trailing edge of said sheet,

means to rotate said supporting portion whereby said sheet engagingportion is moved along said cylinder periphery toward and away from saidgripper means, and

adjustable stop means on said cylinder to limit movement of said sheetengaging portion away from said gripper means.

13 14 19. A sheet handling device as set forth in claim 18 cylinderperiphery toward said gripper means and wherein said sheet engagingportion is the head of an arm resilient means to move said sheetengaging portion whose body comprises an integral portion of saidsupaway from said gripper means. porting portion:

said ar-m being mounted on a shaft within the body of 5 References Citedsaid cylinder, said shaft being driven so as to make said head moveUNITED STATES PATENTS along said cylinder periphery by moving said arm.39961088 7/1963 YOuPg 271 51 20. A sheet handling device as set forth inclaim 18 in 3141667 7/1964 Novlck 271 74 which said means provided torotate said supporting porlo EDWARD SROKA, Primary Emmi-"en tronlncludes mechanical actuators.

said mechanical actuators comprising a cam operated US. Cl. X.R.

lever to move said sheet engaging portion along said 7l74

